Muscle Intro Functions of muscles Movement: respiration, circulation, defecation Stability: resists gravity and provides tension to tendons Communication Heat Production: muscle provides 85% of body heat

Connective Tissue Think of connective tissue as the wrapping that holds muscle bundles together and separates them Endomysium: thin layer that surrounds each muscle cell(fiber) makes room for capillaries and nerve fibers Fascicles: bundles of muscle cells that appear as grain to the naked eye

Connective Tissue Perimysium: A thick connective layer that surrounds each fascicle. Epimysium/Deep Fasciae: a layer that surrounds each muscle Superficial fascia: the layer of connective tissue between the muscle and skin, can be fatty

Anatomy of Muscles Origin: a relatively stationary attachment Belly: thick midregion of muscle Insertion: a relatively mobile attachment Fusiform: muscle thick in the middle thin at ends (biceps brachii) Parallel muscles: straplike muscles uniform with parallel fascicles (sartorius)

Anatomy of Muscles Convergent muscles: Fan-shaped, broad at origin, narrower at insertion Pennate muscles: feather-shaped, fascicles run obliquely to a tendon that runs the length of muscle Circular muscle: Sphincters (eyelids, anus)

Coordinated Action Prime mover: muscle that produces most force during movement Synergist: a muscle that aids the prime mover Antagonist: muscle that resists the prime mover controlling rate of movement Fixator: muscle that prevents a bone from moveing, holds steady